S-Rank Summoner and Ally Support Thread

In Fire Emblem: Awakening, forming bonds and relationships with your characters was a strategic matter. In awakening, you had to think carefully about which units paired with whom. Units with S-Rank had children with each other and that opened up a paralogue for you to unlock their child. The child inherited the skills of their parents and even their stats. Clearing end game content became much easier once you mastered this system in awakening. Awakening brought upon a revival of sorts in the Fire Emblem series by bringing in many new fans. This support system was one of the most popular features in the game.

Now in FE: Heroes, we have a simplified version of this system (with no offspring). I'm interested in seeing who everyone's favorite/most valuable/waifu/husbando/etc... character is.